Pump inlet assemblies for dishwasher appliances

ABSTRACT

A pump inlet assembly and method of operating a dishwasher appliance are provided. The pump inlet assembly includes an inlet conduit providing fluid communication between a sump and a pump. The inlet conduit defines an integrally formed boss which is coupled with a sensor housing using an overmolding process. A pressure sensor is positioned in the sensor housing and is protected from wash fluid by an airgap defined by the boss. The measured pressure may be used to determine the water level within the dishwasher when the pump is not operating and the suction pressure within the inlet conduit when the pump is operating. The inlet conduit, boss, pressure sensor, and pump housing may be integrally formed by injection molding and/or overmolding processes to reduce costs and the likelihood of leaks.

FIELD OF THE INVENTION

The present disclosure relates generally to dishwasher appliances, andmore particularly to improved pump inlet assemblies for dishwasherappliances.

BACKGROUND OF THE INVENTION

Dishwasher appliances generally include a tub that defines a washchamber. Rack assemblies can be mounted within the wash chamber of thetub for receipt of articles for washing. A sump space may be positionedbelow the wash chamber for collecting wash fluid (e.g. variouscombinations of water and detergent along with optional additives).During wash and rinse cycles, a pump can circulate wash fluid from thesump to spray assemblies within the wash chamber. The spray assembliescan apply or direct the wash fluid towards articles disposed within therack assemblies in order to clean such articles.

It is often desirable to know the level of wash fluid within a washchamber of a dishwasher, e.g., to prevent overflow conditions and toensure the level of wash fluid is sufficient for optimal pump operation.Conventional dishwasher appliances may rely on the time a water inletvalve is open to determine how much wash fluid is in the dishwasher.However, variations in the valves or water supply lines, or variation inthe water supply pressure can result in inaccurate water levels.Alternatively, some dishwashers use a variety of sensors for determiningthe level of wash fluid within the dishwasher, e.g., float sensors,capacitive sensors, optical sensors, etc. However, such sensors addsignificant costs and sometime result in reliability issues when exposedto soiled wash fluid.

Certain dishwasher appliances have incorporated the use of pressuresensors positioned within the sump of the dishwasher for determining thelevel of the wash fluid. However, such pressure sensors must beprotected from soil in the wash fluid to prevent contamination. Forexample, such pressure sensors are often connected to the sump with atube to provide an airgap between the wash fluid and the sensor.However, installing these tubes and forming the sump to provide anairgap between the wash fluid and the sensor increases potential leakpoints in the dishwasher.

Accordingly, dishwasher appliances having improved systems and methodsfor determining a level of wash fluid within the dishwasher would beuseful. More specifically, a dishwasher having a pump inlet assemblythat enables reliable pressure sensing with minimal leak points would beparticularly beneficial.

BRIEF DESCRIPTION OF THE INVENTION

The present subject matter provides a pump inlet assembly and method ofoperating a dishwasher appliance. The pump inlet assembly includes aninlet conduit providing fluid communication between a sump and a pump.The inlet conduit defines an integrally formed boss which is coupledwith a sensor housing using an overmolding process. A pressure sensor ispositioned in the sensor housing and is protected from wash fluid by anairgap defined by the boss. The measured pressure may be used todetermine the water level within the dishwasher when the pump is notoperating and the suction pressure within the inlet conduit when thepump is operating. The inlet conduit, boss, pressure sensor, and pumphousing may be integrally formed by injection molding and/or overmoldingprocesses to reduce costs and the likelihood of leaks. Additionalaspects and advantages of the invention will be set forth in part in thefollowing description, may be apparent from the description, or may belearned through practice of the invention.

In accordance with one exemplary embodiment of the present disclosure, adishwasher appliance defining a vertical direction is provided. Thedishwasher appliance includes a wash tub that defines a wash chamber, apump for circulating a flow of wash fluid for cleaning articles placedwithin the wash chamber, and a sump positioned below the wash chamberalong the vertical direction, the sump being configured for collectingwash fluid. A pump inlet assembly includes an inlet conduit providingfluid communication between the sump and the pump and a pressure sensorfor measuring a pressure of the wash fluid in the inlet conduit. A bossis integrally molded with the inlet conduit and defines an airgap. Asensor housing is coupled to the boss above the airgap using anovermolding process, the sensor housing being configured for receivingthe pressure sensor.

In accordance with another exemplary embodiment of the presentdisclosure, a method of manufacturing a fluid circulation assembly of adishwasher appliance is provided. The dishwasher appliance includes apump for circulating a flow of wash fluid for cleaning articles placedwithin a wash chamber and a sump positioned below the wash chamber forcollecting wash fluid. The method includes providing a sensor housingconfigured for receiving a pressure sensor and overmolding an inletconduit onto the sensor housing, the inlet conduit being coupled to thesensor housing by an integral boss which defines an airgap. The methodfurther includes positioning the inlet conduit to establish fluidcommunication between the sump and the pump and positioning the pressuresensor in the sensor housing for measuring a pressure of the wash fluidin the inlet conduit.

According to still another embodiment of the present subject matter, amethod of operating a dishwasher appliance is provided. The dishwasherappliance includes a pump for circulating a flow of wash fluid forcleaning articles placed within a wash chamber, a sump positioned belowthe wash chamber for collecting wash fluid, an inlet conduit providingfluid communication between the sump and the pump, and a sensor housingformed integrally with the inlet conduit and being configured forreceiving a pressure sensor. The method includes measuring the pressureof wash fluid in the inlet conduit and determining whether the pump isoperating.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures.

FIG. 1 provides a front view of an exemplary embodiment of a dishwashingappliance of the present disclosure.

FIG. 2 provides a side cross sectional view of the exemplary dishwashingappliance of FIG. 1.

FIG. 3 is a perspective view of a fluid circulation assembly of theexemplary dishwashing appliance of FIG. 1 according to an exemplaryembodiment of the present subject matter.

FIG. 4 is an exploded perspective view of a pump inlet assemblyaccording to an exemplary embodiment of the present subject matter.

FIG. 5 is a schematic view of the exemplary pump inlet assembly of FIG.4.

FIG. 6 is a schematic view of the exemplary fluid circulation assemblyof FIG. 3 when a pump is operating according to an exemplary embodimentof the present subject matter.

FIG. 7 is a schematic view of the exemplary fluid circulation assemblyof FIG. 3 when the pump is not operating according to an exemplaryembodiment of the present subject matter.

FIG. 8 illustrates a method of manufacturing a fluid circulationassembly and a pump inlet assembly according to an exemplary embodimentof the present subject matter.

FIG. 9 illustrates a method of operating a dishwasher appliance having apump inlet assembly according to an exemplary embodiment of the presentsubject matter.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

As used herein, the term “article” may refer to, but need not be limitedto, dishes, pots, pans, silverware, and other cooking utensils and itemsthat can be cleaned in a dishwashing appliance. The term “wash cycle” isintended to refer to one or more periods of time during the cleaningprocess where a dishwashing appliance operates while containing articlesto be washed and uses a detergent and water, preferably with agitation,to e.g., remove soil particles including food and other undesirableelements from the articles. The term “rinse cycle” is intended to referto one or more periods of time during the cleaning process in which thedishwashing appliance operates to remove residual soil, detergents, andother undesirable elements that were retained by the articles aftercompletion of the wash cycle. The term “drying cycle” is intended torefer to one or more periods of time in which the dishwashing applianceis operated to dry the articles by removing fluids from the washchamber. The term “fluid” refers to a liquid used for washing and/orrinsing the articles and is typically made up of water that may includeadditives such as e.g., detergent or other treatments. The use of theterms “top” and “bottom,” or “upper” and “lower” herein are used forreference only as exemplary embodiments disclosed herein are not limitedto the vertical orientation shown nor to any particular configurationshown; other constructions and orientations may also be used.

FIGS. 1 and 2 depict an exemplary domestic dishwasher 100 that may beconfigured in accordance with aspects of the present disclosure. For theparticular embodiment of FIGS. 1 and 2, the dishwasher 100 includes acabinet 102 having a tub or inner liner 104 therein that defines a washchamber 106. As shown, tub 104 extends between a top and a bottom alonga vertical direction V, between a first side and a second side along alateral direction L, and between a front side and a rear side along atransverse direction T. Each of the vertical direction V, lateraldirection L, and transverse direction T are mutually perpendicular toone another. The tub 104 includes a front opening (not shown) and a door110 hinged at its bottom 112 for movement between a normally closedvertical position (shown in FIGS. 1 and 2), wherein the wash chamber 106is sealed shut for washing operation, and a horizontal open position forloading and unloading of articles from the dishwasher 100. Latch 116 isused to lock and unlock door 110 for access to wash chamber 106.

Upper and lower guide rails 120, 122 are mounted on tub side walls 124and accommodate roller-equipped rack assemblies 126 and 128. Each of therack assemblies 126, 128 is fabricated into lattice structures includinga plurality of elongated members 130 (for clarity of illustration, notall elongated members making up assemblies 126 and 128 are shown in FIG.2). Each rack 126, 128 is adapted for movement between an extendedloading position (not shown) in which the rack is substantiallypositioned outside the wash chamber 106, and a retracted position (shownin FIGS. 1 and 2) in which the rack is located inside the wash chamber106. This is facilitated by rollers 134 and 136, for example, mountedonto racks 126 and 128, respectively. A silverware basket (not shown)may be removably attached to rack assembly 128 for placement ofsilverware, utensils, and the like, that are otherwise too small to beaccommodated by the racks 126, 128. Alternatively, the silverware basketmay be independently mounted within wash chamber 106. It should beappreciated that upper rack assembly 126, lower rack assembly 128, andthe silverware basket may be any suitable size and configuration and maybe mounted within dishwasher 100 in any suitable manner.

The dishwasher 100 further includes a lower spray-arm assembly 140 thatis rotatably mounted within a lower region 142 of the wash chamber 106and above a tub sump portion 144 so as to rotate in relatively closeproximity to rack assembly 128. A mid-level spray-arm assembly 146 islocated in an upper region of the wash chamber 106 and may be located inclose proximity to upper rack 126. Additionally, an upper spray assembly148 may be located above the upper rack 126.

The lower and mid-level spray-arm assemblies 140, 146 and the upperspray assembly 148 are part of a fluid circulation assembly 150 forcirculating water and dishwasher fluid in the tub 104. The fluidcirculation assembly 150 also includes a pump 152 positioned in amachinery compartment 154 located below the tub sump portion 144 (i.e.,bottom wall) of the tub 104, as generally recognized in the art. Pump152 receives wash fluid from sump 144 and provides a flow of wash fluidto a diverter 160. The flow of wash fluid enters diverter 160 through aninlet 162, and diverter 160 directs the flow of wash fluid to one ormore spray assemblies throughout the dishwasher, e.g., to sprayassemblies 140, 146, and 148, or to a silverware spray assembly.

Each spray-arm assembly 140, 146 includes an arrangement of dischargeports or orifices for directing washing liquid received from diverter160 onto dishes or other articles located in rack assemblies 126 and128. The arrangement of the discharge ports in spray-arm assemblies 140,146 provides a rotational force by virtue of washing fluid flowingthrough the discharge ports. The resultant rotation of the spray-armassemblies 140, 146 and the operation of spray assembly 148 using fluidfrom diverter 160 provides coverage of dishes and other dishwashercontents with a washing spray. Other configurations of spray assembliesmay be used as well. For example, dishwasher 100 may have additionalspray assemblies for cleaning silverware, for scouring casserole dishes,for spraying pots and pans, for cleaning bottles, etc. One skilled inthe art will appreciate that the embodiments discussed herein are usedfor the purpose of explanation only, and are not limitations of thepresent subject matter.

The dishwasher 100 is further equipped with a controller 166 to regulateoperation of the dishwasher 100. The controller 166 may include one ormore memory devices and one or more microprocessors, such as general orspecial purpose microprocessors operable to execute programminginstructions or micro-control code associated with a cleaning cycle. Thememory may represent random access memory such as DRAM, or read onlymemory such as ROM or FLASH. In one embodiment, the processor executesprogramming instructions stored in memory. The memory may be a separatecomponent from the processor or may be included onboard within theprocessor.

The controller 166 may be positioned in a variety of locationsthroughout dishwasher 100. In the illustrated embodiment, the controller166 may be located within a control panel area 168 of door 110 as shownin FIGS. 1 and 2. In such an embodiment, input/output (“I/O”) signalsmay be routed between the control system and various operationalcomponents of dishwasher 100 along wiring harnesses that may be routedthrough the bottom 112 of door 110. Typically, the controller 166includes a user interface panel/controls 170 through which a user mayselect various operational features and modes and monitor progress ofthe dishwasher 100. In one embodiment, the user interface 170 mayrepresent a general purpose I/O (“GPIO”) device or functional block. Inone embodiment, the user interface 170 may include input components,such as one or more of a variety of electrical, mechanical orelectro-mechanical input devices including rotary dials, push buttons,and touch pads. The user interface 170 may include a display component,such as a digital or analog display device designed to provideoperational feedback to a user. The user interface 170 may be incommunication with the controller 166 via one or more signal lines orshared communication busses.

It should be appreciated that the invention is not limited to anyparticular style, model, or configuration of dishwasher 100. Theexemplary embodiment depicted in FIGS. 1 and 2 is for illustrativepurposes only. For example, different locations may be provided for userinterface 170, different configurations may be provided for racks 126,128, different spray arm assemblies 140, 146, 148 may be used, and otherdifferences may be applied as well. Moreover, additional racks and/orspray assemblies in any suitable configuration may be included accordingto alternative embodiments.

Referring now to FIG. 3, a portion of fluid circulation assembly 150will be described. As illustrated, sump 144 is placed in fluidcommunication with pump 152 through pump inlet assembly 200. Morespecifically, pump 152 generally includes a motor connected to animpeller through a drive shaft (not shown). The impeller is positionedin an impeller volute or housing 202 for generating a pressure head andselectively pumping wash fluid to spray assemblies 140, 146, 148. Inthis regard, as pump 152 operates, the wash fluid may be drawn throughpump inlet assembly 200 from sump 144.

Referring now also to FIG. 4, an exploded perspective view of pump inletassembly 200 will be described. As illustrated, pump inlet assembly 200generally includes an inlet conduit 210 providing fluid communicationbetween sump 144 and pump 152. Pump inlet assembly 200 also includes aboss 212 that is integrally molded with inlet conduit 210. In thisregard, inlet conduit 210 and boss 212 are integrally formed from asingle, continuous piece of material. According to one embodiment, inletconduit 210 and boss 212 are formed from a resilient material, such asrubber.

Boss 212 is configured to be coupled to a sensor housing 214. Morespecifically, according to the exemplary embodiment, boss 212 and inletconduit 210 are overmolded onto sensor housing 214 to form a singleintegral part. Overmolding is a process by which a previously moldedpart proceeds through a second molding process to add an additionalfeature, material, or component. After the overmolding process iscomplete, pump inlet assembly 200 is a single, integral component thathas few or no leak points and is simple and easy to install.

According to the illustrated embodiment, pump inlet assembly 200 isconstructed by first injection molding sensor housing 214 using a firstmaterial and then overmolding boss 212 and inlet conduit 210 onto sensorhousing 214 using a second material. According to the exemplaryembodiment, inlet conduit 210 and boss 212 are constructed of a softermaterial than sensor housing 214, thus resulting in a single part havingtwo portions with different hardnesses. However, it should beappreciated that the materials used and the method of construction aredescribed herein only for explaining aspects of the present subjectmatter. Pump inlet assembly 200 may use other materials having differenthardness, and may be constructed in a different manner while remainingin the scope of the present invention. For example, sensor housing 214could be overmolded onto inlet conduit 210, the components could be madefrom the same material, etc.

A pressure sensor 216 may be inserted into sensor housing 214 formeasuring the pressure of wash fluid in inlet conduit 210, as describedbelow. Pressure sensor 216 may be any suitable sensor for measuring thepressure of the wash fluid in inlet conduit 210. For example, pressuresensor 216 may be a microelectromechanical (MEMS) type sensor, a bellowtype sensor, etc. According to the exemplary embodiment, pressure sensor216 may be coupled to controller 166, which may be configured forcontrolling dishwasher 100 in response to feedback from pressure sensor216.

According to the illustrated embodiment, pump inlet assembly 200 isconnected from a bottom portion of sump 144 and is connected directly toimpeller housing 202. More specifically, ends of inlet conduit 210 areconnected to sump 144 and impeller housing 202 using screw clamps.However, according to alternative exemplary embodiments, pump inletassembly 200 may be overmolded onto sump 144, impeller housing 202, orboth. In this manner, one or both screw clamps may be eliminated,assembly may be simplified, and the likelihood of leaks may be reducedeven further.

Referring now generally to FIGS. 4 through 7, inlet conduit 210 ispositioned and oriented such that boss 212 is located at an uppermostposition along the vertical direction V. Moreover, boss 212 isconfigured for defining an airgap 220 between pressure sensor 216 andthe wash fluid within inlet conduit 210. Airgap 220 provides spacebetween the wash fluid within inlet conduit 210 and pressure sensor 216.This may be important, for example, to prevent contact of wash fluidwith pressure sensor 216, which may build up dirt and grime over time,thereby affecting measurement accuracy. Although boss 212 is illustratedas defining airgap 220 having an arcuate profile, it should beappreciated that airgap 220 may be formed in any suitable size or shape.

After assembling pump inlet assembly 200 and using it to couple sump 144and pump 152, pressure sensor 216 may be used to reliably and accuratelymeasure the pressure of wash fluid in inlet conduit 210. The pressuremeasurement may be correlated to various performance characteristics ofdishwasher 100 and may be used to control dishwasher operation. Forexample, dishwasher 100 may include a fluid inlet (not shown) thatsupplies water or wash fluid to wash chamber 106 for use by fluidcirculation assembly 150 during operation. The fluid inlet may becontrolled in response to pressure measurements, for example, to adjustthe level of wash fluid within wash chamber 106, as described below.

FIG. 8 illustrates a method 250 for constructing pump inlet assembly200. Notably, method 250 results in a leak-free, easy to installassembly that is capable of receiving pressure sensor 216. Moreover,method 250 integrates an airgap 220 between the wash fluid within inletconduit 210 and pressure sensor 216 to ensure long-term, reliableoperation of pressure sensor 216 with little risk of soil build-up.

Method 250 includes, at step 252, providing a sensor housing configuredfor receiving a pressure sensor. For example, according to oneembodiment, sensor housing may be injection molded using acrylonitrilebutadiene styrene (ABS) thermoplastic, polypropylene, or any othersuitable plastic or material. Step 254 includes overmolding an inletconduit onto the sensor housing. As explained above, the inlet conduitis a circular conduit having a channel or boss extending from thecenter. The boss extends between and couples the inlet conduit and thesensor housing. In addition, the boss defines an airgap between theinlet conduit and the sensor housing.

Method 250 further includes, at step 256, positioning the inlet conduitto establish fluid communication between the sump and the pump. Forexample, the inlet conduit may be fluidly coupled at a bottom portion ofsump and to the impeller housing of the pump. At step 258, method 250includes positioning the pressure sensor in the sensor housing formeasuring a pressure of the wash fluid in the inlet conduit.

Now that the construction and configuration of fluid circulationassembly 150 and pump inlet assembly 200 according to an exemplaryembodiment of the present subject matter has been presented, anexemplary method 300 for operating a dishwasher according to anexemplary embodiment of the present subject matter is provided. Method300 can be used to operate any suitable dishwashing appliance or otherwater consuming appliance. For example, method 300 may be utilized tooperate dishwasher 100 (FIG. 1) to control water levels within washchamber 106 and ensure cavitation does not occur in pump 152. In thisregard, for example, controller 166 or another dedicated controller maybe programmed to implement method 300.

Referring now to FIG. 9, method 300 includes, at step 310, measuring thepressure of wash fluid in the inlet conduit. Step 320 includesdetermining whether the pump is operating. Based on the pump operationalstate and the measured pressure in the inlet conduit, method 300 caninclude making a variety of determinations and performing variousactions in response. For example, using dishwasher 100 and pump inletassembly 200 as an example, controller 166 can receive pressuremeasurements (i.e., signals corresponding to pressure measurements) frompressure sensor 216. In response to the pressure measurements or othersystem feedback, controller 166 may, for example, determine whether pump152 is operating, determine the water level within wash chamber 106, andinitiate an action such as starting or stopping the flow of waterthrough a fluid inlet. Although exemplary actions are described hereinfor the purpose of explaining aspects of method 300, it should beappreciated that the pressure sensor integrated into the inlet conduitmay be used for making other determinations and performing otheractions.

For example, method 300 includes, at step 330, determining a fluid levelwithin the sump based on the measured pressure of the wash fluid whenthe pump is not operating. In this regard, the measured pressure cancorrespond to a particular height of wash fluid within a chamber of adishwashing appliance. According to exemplary embodiments, a calibrationcurve may be used to relate the measured pressure and the fluid levelwithin the sump. At step 332, method 300 includes determining that thefluid level within the sump has exceeded a predetermined threshold andstep 334 includes initiating an action in response to determining thatthe fluid level has exceeded the predetermined threshold.

According to one embodiment, the predetermined threshold is a maximumfluid level of the dishwasher and the initiated action is shutting off aflow of fluid into the dishwasher. Using such a limit may preventoverflow conditions. Alternatively, the predetermined threshold may be adesired fill amount for an operating cycle of the dishwasher and theinitiated action is shutting off a flow of fluid into the dishwasher andstarting the operating cycle. In this regard, for example, if only asmall amount of water is required for a particular operating cycle,method 300 may be used to supply only that amount of wash fluid, therebyresulting in energy and water savings.

According to another exemplary embodiment, method 300 includes, at step340, determining a suction pressure of the pump based on the measuredsuction pressure of the wash fluid when the pump is operating. Thesuction pressure may be used to confirm proper operation of dishwasherand the circulation pump. Method further includes, at step 342,determining that the measured suction pressure is unstable, and at step344, initiating an action based on the determination that the measuredsuction pressure is unstable. As used herein, suction pressure isconsidered “unstable” when it varies beyond a predetermined rangerelative to the desired operating pressure. For example, the measuredsuction pressure may be unstable if the measured suction pressure fallsbelow a low pressure threshold, exceeds a high pressure threshold, orvaries beyond a variability limit. The action taken in response to thedetermination that the suction pressure is unstable often includesadjusting the fluid level in the wash chamber. For example, theinitiated action may include adding fluid to the dishwasher until themeasured suction pressure stabilizes. However, it should be appreciatedthat other actions are also possible.

Notably, by constructing pump inlet assembly 200 as a single, integralpiece, assembly is simplified, the number of parts is reduced, and thelikelihood of leaks is minimized. Therefore, pump inlet assembly 200reduces costs while increasing the performance and reliability ofdishwasher 100.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A dishwasher appliance defining a verticaldirection, the dishwasher appliance comprising: a wash tub that definesa wash chamber; a pump for circulating a flow of wash fluid for cleaningarticles placed within the wash chamber; a sump positioned below thewash chamber along the vertical direction, the sump being configured forcollecting wash fluid; and a pump inlet assembly comprising: an inletconduit providing fluid communication between the sump and the pump; apressure sensor for measuring a pressure of the wash fluid in the inletconduit; a boss integrally molded with the inlet conduit, the bossdefining an airgap; and a sensor housing coupled to the boss above theairgap using an overmolding process, the sensor housing being configuredfor receiving the pressure sensor.
 2. The dishwasher appliance of claim1, wherein the sensor housing is formed by injection molding, andwherein the inlet conduit and the boss are overmolded directly to thesensor housing.
 3. The dishwasher appliance of claim 1, wherein theinlet conduit is coupled to the sump proximate a bottom of the sump. 4.The dishwasher appliance of claim 1, wherein the inlet conduit ispositioned and oriented such that the boss is disposed at an uppermostposition along the vertical direction.
 5. The dishwasher appliance ofclaim 1, further comprising a controller in operative communication witha fluid inlet for controlling a flow of water into the wash chamber andthe pressure sensor, wherein the pressure sensor measures the pressureof the wash fluid when the pump is not operating and the controllerdetermines a fluid level within the wash chamber based on the pressuremeasurement.
 6. The dishwasher appliance of claim 5, wherein thecontroller is configured for stopping the flow of water from the fluidinlet when the measured fluid level reaches a predetermined threshold.7. The dishwasher appliance of claim 1, further comprising a controllerin operative communication with a fluid inlet for controlling a flow ofwater into the wash chamber and the pressure sensor, wherein thepressure sensor measures the pressure of the wash fluid when the pump isoperating and the controller determines a suction pressure of the pumpbased on the pressure measurement.
 8. The dishwasher appliance of claim7, wherein the controller is configured for the flow of water from thefluid inlet after the measured suction pressure stabilizes at apredetermined threshold.
 9. A method of manufacturing a fluidcirculation assembly of a dishwasher appliance, the dishwasher appliancecomprising a pump for circulating a flow of wash fluid for cleaningarticles placed within a wash chamber and a sump positioned below thewash chamber for collecting wash fluid, the method comprising: providinga sensor housing configured for receiving a pressure sensor; overmoldingan inlet conduit onto the sensor housing, the inlet conduit beingcoupled to the sensor housing by an integral boss which defines anairgap; positioning the inlet conduit to establish fluid communicationbetween the sump and the pump; and positioning the pressure sensor inthe sensor housing for measuring a pressure of the wash fluid in theinlet conduit.
 10. The method of claim 9, wherein the pressure sensormeasures the pressure of the wash fluid when the pump is not operatingto determine a fluid level within the wash chamber.
 11. The method ofclaim 9, wherein the pressure sensor measures the pressure of the washfluid when the pump is operating to determine a suction pressure of thepump.
 12. The method of claim 9, wherein positioning the inlet conduitto establish fluid communication between the sump and the pump comprisesovermolding the inlet conduit to a pump housing.
 13. A method ofoperating a dishwasher appliance, the dishwasher appliance comprising apump for circulating a flow of wash fluid for cleaning articles placedwithin a wash chamber and a sump positioned below the wash chamber forcollecting wash fluid, the method comprising: measuring the pressure ofwash fluid in an inlet conduit which provides fluid communicationbetween the sump and the pump, a sensor housing being formed integrallywith the inlet conduit and being configured for receiving a pressuresensor; and determining whether the pump is operating based on thepressure measurement from the pressure sensor.
 14. The method of claim13, further comprising determining a fluid level within the sump basedon the measured pressure of the wash fluid when the pump is notoperating.
 15. The method of claim 14, further comprising: determiningthat the fluid level within the sump has exceeded a predeterminedthreshold; and initiating an action in response to determining that thefluid level has exceeded the predetermined threshold.
 16. The method ofclaim 15, wherein the predetermined threshold is a maximum fluid levelof the dishwasher and the initiated action is shutting off a flow offluid into the dishwasher.
 17. The method of claim 15, wherein thepredetermined threshold is a desired fill amount for an operating cycleof the dishwasher and the initiated action is shutting off a flow offluid into the dishwasher and starting the operating cycle.
 18. Themethod of claim 13, further comprising determining a suction pressure ofthe pump based on the measured suction pressure of the wash fluid whenthe pump is operating.
 19. The method of claim 18, further comprising:determining that the measured suction pressure is unstable; andinitiating an action based on the determination that the measuredsuction pressure is unstable.
 20. The method of claim 19, wherein themeasured suction pressure is unstable if the measured suction pressurefalls below a low pressure threshold or varies beyond a variabilitylimit, and wherein the initiated action is adding fluid to thedishwasher until the measured suction pressure stabilizes.